To remain healthy, cells, in particular mammalian cells, need to maintain a balance between oxidizing and reducing conditions, sometime referred to as redox state/potential. Reactive oxygen species (ROS), including peroxides, are implicated in cellular activity and metabolism.
Effects of ROS on cell metabolism have been well documented in a variety of species. These include not only a role in apoptosis, but also in the induction of host defense genes and mobilization of ion transport systems. ROS are implicated in redox signaling, also known as oxidative signaling. In addition, ROS are implicated in cellular activity to a variety of inflammatory responses including cardiovascular disease. In general, harmful effects of ROS on a cell include: (a) damage of DNA; (b) oxidation of polyunsaturated fatty acids in lipids (lipid peroxidation); (c) oxidation of amino acids in proteins; and (d) inactivation of certain enzymes by oxidation of co-factors.
Hydrogen peroxide is generated in a variety of ways within the cell. Enzymes such as the monoamine oxidases produce hydrogen peroxide as a product of their enzymatic activity. Hydrogen peroxide can also be formed by interconversion of other reactive oxygen species such as that produced by superoxide dismutase when reacting with superoxide.
Current hydrogen peroxide detection techniques, such as AmplexRed, have several limitations including: requiring horseradish peroxidase, requiring an enzyme coupled assay, instability in the presence of thiols such as DTT, 2-mercaptoethanol, etc., and instablity at pH (>8.5).